A Novelty-Induced Change in Episodic (NICE) Context Account of Primacy Effects in Free Recall

Eddy J Davelaar

doi:10.4236/psych.2013.49099

Abstract

Formal cognitive models of episodic memory assume that during encoding list items become associated with a changing context representation. However, this representation is recency-biased and thus can not account for primacy effects under conditions that prevent rehearsal. In this paper, it is hypothesized that one source underlying primacy effects is the detection of novelty. In three experiments, it is shown how novelty at the perceptual and semantic level can explain the full serial position function of first recall probabilities, including primacy effects. It is proposed that an item becomes distinctive due to increase in the change within a distributed episodic context representation, induced by novelty detection. The theory makes three assumptions. First, items become associated with a distributed context representation. Second, the context representation changes with item presentation. Third, the rate of contextual change is related to the perceptual and conceptual difference computed between the presented item and the previous item (or items in the buffer). This theory captures primacy effects in first recall probabilities without recourse to a rehearsal process and provides a mechanistic account of distinctiveness.

Highlights

One of the most robust results in cognitive psychology is the U-shaped serial position curve obtained in the immediate free recall task (Murdock, 1962)
Many dual-store and dual-trace models assume that the first item enters an empty short-term memory (STM) buffer from which it is displaced after the buffer is filled to capacity, leading to that item residing in STM longer than subsequent items
As episodic trace strength is a function of the duration that items reside in the buffer, the episodic trace for the first item will be stronger than subsequent items (Atkinson & Shiffrin, 1968; Davelaar et al, 2005; Raaijmakers & Shiffrin, 1980)

Summary

Introduction

One of the most robust results in cognitive psychology is the U-shaped serial position curve obtained in the immediate free recall task (Murdock, 1962). In the second type of rehearsal explanation, increased rehearsal opportunities for the first few items lead to increased probabilities that the items are still in the rehearsal cue at the end of the list presentation This rehearsal-enhanced accessibility of the items is assumed in the more recent work on rehearsal (Tan & Ward, 2001) in which no short-term buffer is presumed. This denial of a shortterm buffer requires that such models liken the rehearsal process that occurs during list presentation to mini-retrievals (Ward, 2002; see Laming, 2006). The explanations in terms of buffer-enhanced encoding, rehearsal-enhanced encoding, rehearsal-enhanced accessibility, and distinctiveness all capture the basic pattern, they are not mutually exclusive

Results

Discussion

Conclusion